I have a pair of small block mopar heads on a 360 engine that I cannot identify. The block is from 1979, the intake manifold is 1969ish, so no real clues there. The heads are cast iron and do not have the typical 7 digit casting number under the valve cover, nor do they have the typical 340 or 360 casting number. There is a 16M cast into the top of one of the intake runners where the 340 or 360 would normally be. There are a few other small markings, the number 74 and a time clock symbol but that's about it. Could it be another manufacturer other that Chrysler? The motor is still in a running truck, so I'm a little limited on the info I can provide.
Need help identifying SBM cast iron head
- Thread starter Earlie A
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Professor Fate
Push the button, Max...
It's not much help on an assembled, running motor, but late SBM heads have the casting number on the underside of the head on an intake runner.
Maybe you can pop off a valve cover and sneak a peek of it with a borescope.
Maybe you can pop off a valve cover and sneak a peek of it with a borescope.
Any idea what the engine is out of? It might possibly be an industrial/heavy duty head. Seen an industrial 360 with similar head markings before.
Thanks. I suspect these heads are probably 1979 like the block.
I do not. I haven't tried to get the serial number yet. Guess I should.
Where have you been??? Did you go on vacation. Lol
Dartswinger70
Well-Known Member
I think the late 360 heads dont have a j or 360 on them youd have to pull the intake then use a mirror maybe? I wonder if they are aftermarket cast iron?
Professor Fate
Push the button, Max...
Does it have exhaust valve rotators on it? That would assure that it's a late head, most likely with 1.88 intakes in it.
The enlarged exhaust port flanges for air injection bosses would also be a giveaway for '74ish and later heads.
Yes it does. What year did that start?
Several things. Out of town, bought an old truck and daughter is getting married in 3 months and I have to get her house renovation finished. I'm starting to feel the pressure.
You got this.
Professor Fate
Push the button, Max...
'73-'74 ish, depending on application.
The next time he touches a grinder Speedmaster heads may not even be being made. Lol
PRH
Well-Known Member
The heads with ex rotators usually came on 3/4 ton and up, and/or industrial applications.
Some of that style 360 came with the intake heat crossover being water instead of exhaust.
The only heads I’ve seen like that in person were closed chamber and had 1.78/1.50 valves and 318 sized ports.
As I recall, the water crossover heads don’t have the air gap pocket on the intake flange by the crossover.
So, if the pocket is there, it’s not those heads.
I did a little “googling”, and I found some info I had forgotten on the HD heads.
They use 18mm spark plugs.
Here’s the crossover:
Some of that style 360 came with the intake heat crossover being water instead of exhaust.
The only heads I’ve seen like that in person were closed chamber and had 1.78/1.50 valves and 318 sized ports.
As I recall, the water crossover heads don’t have the air gap pocket on the intake flange by the crossover.
So, if the pocket is there, it’s not those heads.
I did a little “googling”, and I found some info I had forgotten on the HD heads.
They use 18mm spark plugs.
Here’s the crossover:
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Professor Fate
Push the button, Max...
Well, I've got a stock '79 E58 360 (ex police 4 bbl.) sitting under the bench that has rotators, and a '88 roller 318 with 302 heads and rotators, and a '92 360 TBI roller motor with 308 heads and rotators; so they're not necessarily just on the Industrial/HD truck motors.
The 234 industrial castings have water crossover instead of exhaust, it’s possible that there are some other casting numbers for water crossover heads, though. The 360 industrial heads I’ve seen were 857 casting with exhaust instead of water crossover and 273/318 size ports with 18mm spark plugs. In hindsight, I wish we had bore scope them to see if they were open or closed chamber.
PRH
Well-Known Member
My understanding is the lil red engines used the “340” cam profile.
The heads that use ex rotators have really short ex valve springs, which I don’t think are compatible with the HP cam.
The heads that use ex rotators have really short ex valve springs, which I don’t think are compatible with the HP cam.
PRH
Well-Known Member
Just measure the lift.
Edit-
I’m def not any kind of expert on what SBM factory engine packages included what parts.
I did a little digging and came across some info claiming the ‘79 LRE engines didn’t get the HP cam.
True or not, I have no idea.
Edit-
I’m def not any kind of expert on what SBM factory engine packages included what parts.
I did a little digging and came across some info claiming the ‘79 LRE engines didn’t get the HP cam.
True or not, I have no idea.
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It sounds like you really can't identify what they are without pulling them.
PRH
Well-Known Member
That’s good info.
I don’t recall ever seeing a set of those.
PRH
Well-Known Member
I’ve had good results taking the largest and smallest dimensions, and using the difference as lobe lift.
It doesn’t need to be down to the thou accuracy since there is a fair amount of lift difference between the factory cams.
For example, I have a used replacement SB cam here.
No numbers on it.
Measuring both an intake and exhaust lobe with a caliper showed .271 lobe lift on both(1.616-1.345).
This is very close to the 360 low performance/2 bbl cam that’s .410/.410 lift.
Edit- I put the cam in the lathe and checked the lift with an indicator.
I was pretty close with the caliper measurement……..it was .273 when checking the same two lobes in the lathe.
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